TPS problem?

yOnKiNaToR · 01-31-2002, 04:13 PM

well, after having to drive in 1st or 2nd gear through town b/c of an accident, i'm really getting sick of the bucking i'm getting. if i try to keep the throttle steady at real low speed, the car almost gives itself more gas even though i'm not pressing the pedal. the car does it at any speed but the severity decreases as i get in a higher gear and higher speed. it also happens when i decelerate. it really pulls me back even if i lift off the throttle gently.

i then checked the idle and noticed that it surges a tiny bit but nothing like 800-1100 rpm like i've heard of before. another thing i did notice that was much more apparent was that when i revved it up and let off the gas, as soon as it hit 1000 rpm or so, it would raise another 100-200 rpm then fall back down to regular idling of 800..is that normal?

could this be the TPS? i have the throttle position sensor and throttle body assembly out of my car right now. where should those 2 adjustment screws be? one screw is at the dead top and the other is at the dead bottom. should they be adjusted a little more towards the middle?

Roger Hall · 01-31-2002, 06:47 PM

my 81 924 has the same problem I have richened the fuel mixture and the problem seems to be improving.

yOnKiNaToR · 01-31-2002, 06:56 PM

how did you richen the fuel mixture?

i think i'm gonna keep guessing and checking by adjusting those screws both ways to see what it does but it takes so long just to get the TPS + throttle body in and out of there.

newoldguy · 01-31-2002, 10:09 PM

Yo Yonkinator,
I don't know about the idle mixture. But with regard to the TPS, you might check back to last fall - Sept or so. I was having trouble and we did a lot of talking about this. Basically, if I remember right, the TPS is adjusted correctly if it "clicks" just as it closes fully, or, as it just opens from the closed position. On my car I remember that it was turned (can't remember if clockwise or counterclockwise) but it was at the limits of the adjusting screws so that part may be OK. Also, I believe you can check for it working by following the troubleshooting that we shared. Basically, you get either an open or closed circuit (check with voltmeter) when the throttle is fully closed or fully open between the connector spades on the TPS. I think the Haynes manual discusses this procedure. Good luck!

yOnKiNaToR · 02-02-2002, 05:19 PM

i have also found another related problem: i cannot rev it anywhere between 1200 rpms and 2000...if i try to rev it to say 1,500, it will rise to 2000 no matter how soft i am on the pedal..i even tried using my finger on the gas pedal as light as i could and it either stays at idle, or rises to 2,000.

anybody have any idea what else could it be b/c my TPS looks fine.

Roger Hall · 02-02-2002, 05:49 PM

there is a small hole between the fuel distributor and the rubber boot inset a long allen wrench a 3 milimeter i think and turn clockwise to richen the fuel mixture

yOnKiNaToR · 02-15-2002, 02:05 PM

fuel distributor? do you mean fuel pump or something else? where is it located? (sorry, not much experience with cars but working on it)

drew1 · 02-15-2002, 03:10 PM

I think Roger is talking about a 924. You can play with your vane air flow meter on a 944. Maybe you ought to look for vacuum leaks, faulty fuel pressure regulator, etc.

drew1

Roger Hall · 02-15-2002, 07:50 PM

sorry i am refering to my 81 924

yOnKiNaToR · 02-15-2002, 08:06 PM

well, i have so many problems right now, i ought to just take it somewhere to get it inspected... they can prolly tell me what is wrong with my car instead of spending forever trying to figure it out myself. anybody know average costs of something like that?

Afterburner951NOS · 02-16-2002, 04:59 PM

haha TPS reports. ahh, good times. Glad I could make a contrbution!

Sam